Key members of the development team on Bioshock Infinite have left Irrational Games, raising questions about the state of the highly anticipated title, sources tell Gamasutra.

Tim Gerritsen, director of product development, and art director Nate Wells have both announced their departure. Wells was a 13 year veteran of the studio, whose distinctive style was heralded in the original Bioshock.

Wells confirmed his departure via his Twitter feed, changing his bio to "New Job … Details to follow" earlier today. (He has since changed it again after members of the NeoGAF forums began speculating about the circumstances of his career shift.)

His LinkedIn page briefly listed Naughty Dog among his employers in 2012, leading to speculation he had joined the Uncharted developer. He has since removed that – and updated the page to reflect his departure from Irrational.

Gerritsen lists his employment at Irrational as having ended this month on his LinkedIn page. While at the company, he directly managed the content creators for Bioshock Infinite and listed his duties as "interfacing with our corporate home base and publishing partners, strategic level partners and vendors, conducting contract negotiation, strategic level planning, hiring and recruitment, and supervising our day to day development."

Before his tenure at Irrational, Gerritsen was chairman and business director at Human Head Studios.

Gamasutra was unsuccessful in efforts to reach Gerritsen and Wells. An inquiry to Irrational president Ken Levine was not returned.

[UPDATE: Levine did acknowledge Wells' departure via Twitter, though, telling followers "Scott Sinclair, art director of Bio1, back in the art director's chair for Infinite to bring it home. Can't wait to show you what's cooking."]

First announced in 2010, Bioshock Infinite is one of Take-Two's most important games this fiscal year. Previously set for an Oct. 16 launch, Irrational announced a delay in the weeks before E3 with studio head Ken Levine announcing the game would ship instead on Feb. 26, 2013.

"I won’t kid you: Bioshock Infinite is a very big game, and we’re doing things that no one has ever done in a first-person shooter," Levine wrote. "We had a similar experience with the original Bioshock, which was delayed several months as our original ship date drew near. Why? Because the Big Daddies weren’t the Big Daddies you’ve since come to know and love. Because Andrew Ryan’s golf club didn’t have exactly the right swing. Because Rapture needed one more coat of grimy Art Deco. The same principle now applies to Bioshock Infinite."

The game was not shown at E3 and will not be on display at Germany's GamesCom show.

"The next time you see our game, it will be essentially the product we intend to put in the box," Levine said.

The delay and Irrational's decision to sequester itself led to concerns among fans that development on the game had run into troubles. Those concerns have not abated in the subsequent months.

While there have been no indications by the company of any shift in the game's release date, the departures of key team members raises questions. And some industry analysts are skeptical whether Bioshock Infinite will arrive on time.